In 1990 I got sick of ham radio and sold my HF station, a perfectly
good TS-430S, with CW filter, and external power supply/speaker kit,
along with a Heathkit SB-200 kilowatt linear amplifier. The
antenna
situation where I lived was awful, and there was no good way, it
seemed, to solve the problem. For various reasons,
I lost
interest,
and sold all of the HF equipment. That didn't last long,
though. In
1991, I decided that I could solve some of the problems, and replaced
the old station with an Icom IC-735, along with an MFJ-989C antenna
matching network. I also figured out that I had a good enough
location
to install an HF vertical antenna, and installed a Cushcraft V-7
groundless vertical. So I was back on the air.

In 1991, the IC-735 was at the end of a very long production
run.
Icom
had been making these for nearly eight years, and the IC-735 was a
mature design. Because it was discontinued, I got a better
than
usual
price for the radio. The IC-735 was one of those radios that
you
would
see in the non-big-gun DX stations pictured in QST and CQ. It
was
a
cost-effective solution for those who needed a competent rig, and
needed it to not cost too much. This was nothing fancy, but
it
always
worked when I turned it on, and sounded good on the air. I
kept
this
radio from 1991 until 2004, when I sold it to pay for the first big
round of bills from my cancer surgery.

Features

Excellent
Transmit Audio
– The Icom IC-735 had good punchy transmit audio, when
combined
with the microphone that came with it. Icom had settled on
high-output amplified electret microphones, and as long as the user
stuck with one of those, the radio sounded very good. It
could be
heard through a crowded pile-up. For SSB there were two
cascaded
SSB filters, which allowed Icom to include an RF speech processor in
the IC-735. This boosted the average transmitted SSB power
significantly, without widening the transmitted signal at
all.
For SSB, it was a fine transmitter.

Pretty
Good SSB Receive
– The Icom IC-735 was the first radio I ever owned which had
two
cascaded IF crystal filters, with the ability to shift the frequency
for one of the IFs, which could be used to narrow the received
bandwidth without buying any more filters. This only worked
for
SSB, unfortunately, as when the CW filter was engaged, there was no
second CW filter to shift. For SSB it was a good receiver for
its
day. It certainly outperformed the TS-430 I had before it in
this
regard.

Simple
Controls –
The Icom IC-735 did not have a lot of features to control, and all of
them were accessible from the front panel. The usual controls
were out there in front, but then Icom put a little transparent gray
cover over a bunch of tiny controls for those things which were
lesser-used. Unfortunately, this included such things as the
switch for the CW filter, microphone gain, and other commonly used
features. IF someone were using the IC-735 mobile,
strictly
on SSB, that little door would have been no real problem, but for the
user who used all of the radio, that door became a weak spot in the
design. If you look at these on eBay, you will find that many
of
them no longer have the little door, it having been lost long ago, as
some user simply removed the door as a useless thing, or broke it,
since it was made from really cheap plastic.
Furthermore,
some controls were simply too small for their function. An
example of this is the notch knob, which controlled a tunable notch to
get rid of carriers and such. The problem is that the knob is
so
small, and the tuning so finicky, that it was simply too much trouble
to tune out the occasional carrier.

Full
Break-In CW – sort of
anyway. The Icom
IC-735 could be set to operate in a
full-break-in mode, and if the user were not excessively fast, it did
an OK job. The limitations were the relays in the T/R
circuitry,
which had to follow the keying. The relays were rather loud,
and
the keying waveforms were not particularly good in full-break-in
mode. Furthermore, the receiver did not recover between dits,
and
so what the operator got was pretty close to full-break-in, but not
done particularly well. At 10 words per minute, it worked
well
enough; at 25 words per minute it might as well not have been
called full break-in.

Mediocre
CW receive filtering
– I installed the proper CW filter in the Icom IC-735, and it
did
help with CW reception in a crowded band. however, there was
a
lot of “blow-by” and the ultimate rejection of the
CW
filter seemed to be less than 30 dB. Furthermore, the Pass
Band
Tuning did not work with CW, as the 2nd IF filter in the CW mode was
the normal SSB filter. This CW filtering issue was the single
most annoying behavior of the Icom IC-735.

As a basic radio, the Icom IC-735 was a reasonable choice. If
the
operator used only SSB (or FM for that matter) the radio did a pretty
good job. Certainly, it was a good buy for the
price. Any
CW operator, however, would find that the Icom IC-735 was lacking in
features which are really needed for use in today's crowded bands.

73

Diehl Martin
W4TI
July 2006

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